Step 1 : Firstly, duplicate product template and edit product details. Refer here.
Step 2 : From dashboard, on the left menu, go to: Products > Advanced Bulk Edit
Step 3 : To show list of products, filter the product name and click get products.
Step 4 : To show other column settings, click Show/Hide fields. After you done choosing which column to show, click OK.
Step 5 : To edit product image or gallery, just click on the column section shown.
Step 6 : After you click image gallery column on certain product, a popup will appear. Here you can add, remove or rearrange the images. When done edit, click Save.
Step 7 : To edit SKU, weight or stock quantity, just click on the column.
Step 8 : Lastly, after done edit click Save Changes.